A.I.R pump on 83 Riv

Hi, I own an 83 Riv with a seized A.I.R. pump. The car wants to backfire on acceleration, occasonally sets a code 13 for o2 sensor, lacks some power and has become a gas hog. I've replaced all ignition. Should I replace the smog pump first or the o2? What are the ramifications of leaving the A.I.R disabled. Thanks

the air pump has nothing to do w/ your code 13.. make sure you dont have any vacum leaks and if you dont replace the o2 sensor.. a seized air pump wont cause a running problem, it is for emmisions. the air pump, pumps fresh air into the exh when the car is running rich while warming up to bring the emmisions down to the set specs.. when i had my 83 i took all that air crap off and plugged the holes on the exh manifolds w/ comon pipe thread fittings